Various cleanups and fixes I have no idea about...

.gitignore

Makefile

doc.md

include/class.h

include/dfa.h

include/nfa.h

include/parse.h

include/regex.h

src/class.c

src/dfa.c

src/main.c

src/nfa.c

src/parse.c

src/regex.c

src/test.c

user_documentation.md